KR20190034138A - Refrigerator oil - Google Patents

Abstract

[상기 화학식 A 중, R^a 및 R^b는 각각 독립적으로 1가의 탄화수소기를 나타내고, R^c는 2가의 탄화수소기를 나타내고, X는 극성 기를 나타내고, Z^a 및 Z^b는 각각 독립적으로 산소 원자 또는 유황 원자를 나타낸다]The present invention provides a refrigerator oil containing a lubricating base oil and a compound represented by the following formula (A).
(A)

[Wherein R ^a and R ^b each independently represent a monovalent hydrocarbon group, R ^c represents a divalent hydrocarbon group, X represents a polar group, Z ^a and Z ^b each independently represents an oxygen atom or a sulfur atom Lt; / RTI &

Description

Refrigerator oil

The present invention relates to refrigerator oil (refrigerator oil).

Refrigerators such as a refrigerator, a car air conditioner, a room air conditioner, and a vending machine are provided with a compressor for circulating the refrigerant in the refrigeration cycle. The compressor is filled with refrigerating machine oil for lubricating the sliding member. Characteristics of the refrigerator oil such as abrasion resistance and stability are required.

The refrigerator oil generally contains a lubricating base oil and an additive selected according to the required properties as described above. Conventionally, as additives (wear-resistant agents) for improving wear resistance, positive phosphate esters, acidic phosphate esters and the like have been used (for example, Patent Documents 1 and 2).

Japanese Patent Application Laid-Open No. 11-256182 Japanese Patent Application Laid-Open No. 2000-282076

However, refrigerator oils containing a polyphosphoric acid ester or an acidic phosphate ester as a wear-resistant agent still have room for improvement in terms of abrasion resistance. In addition, the acidic phosphate ester exhibits high abrasion resistance as compared with the polyphosphoric acid ester, but may have a problem in terms of stability.

Under such circumstances, the inventors of the present invention focused on improvement of abrasion resistance and developed refrigerator oil. That is, an object of the present invention is to provide a refrigerator oil excellent in wear resistance.

The present invention provides a refrigerator oil containing a lubricating base oil and a compound represented by the following formula (A).

(A)

[Wherein R ^a and R ^b each independently represent a monovalent hydrocarbon group, R ^c represents a divalent hydrocarbon group, X represents a polar group, Z ^a and Z ^b each independently represents an oxygen atom or a sulfur atom Lt; / RTI &

The refrigerator oil preferably contains, as a lubricating oil base oil, at least one kind of acidic (oxygen-containing) oil selected from the group consisting of esters and ethers.

The refrigerator oil preferably further contains an epoxy compound.

The refrigerator oil preferably contains, as the epoxy compound, a glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an oxirane compound, an alkyloxirane compound, an alicyclic epoxy compound, an epoxidized fatty acid monoester, And at least one selected from the group consisting of plant-derived vegetable oils.

The refrigerator oil preferably contains at least one selected from the group consisting of a glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound and an alicyclic epoxy compound as an epoxy compound.

The polar group represented by X in formula (A) preferably has an oxygen atom.

According to the present invention, it is possible to provide a refrigerator oil excellent in wear resistance.

Hereinafter, embodiments of the present invention will be described in detail.

The refrigerator oil according to one embodiment contains a lubricating base oil and a compound represented by the following formula (A).

(A)

[Wherein R ^a and R ^b each independently represent a monovalent hydrocarbon group, R ^c represents a divalent hydrocarbon group, X represents a polar group, Z ^a and Z ^b each independently represents an oxygen atom or a sulfur atom Lt; / RTI &

As the lubricant base oil, hydrocarbon oil, propylene oxide or the like can be used. Examples of the hydrocarbon oil include a mineral oil hydrocarbon oil and a synthetic hydrocarbon oil. Examples of the propionic acid include esters, ethers, carbonates, ketones, silicones and polysiloxanes.

The mineral oil hydrocarbon oil can be obtained by subjecting a lubricating oil fraction obtained by distillation and distillation of crude oil such as paraffin oil and naphthene oil to distillation under reduced pressure, solvent purification, hydrogenation purification, hydrogenolysis, solvent bleeding, Followed by treatment, purification with sulfuric acid, and the like. These purification methods may be used singly, or two or more kinds may be used in combination.

Examples of the synthetic hydrocarbon solvent include alkylbenzene, alkylnaphthalene, poly-alpha -olefin (PAO), polybutene, and ethylene- alpha -olefin copolymer.

As the alkylbenzene, the following alkylbenzene (A) and / or alkylbenzene (B) can be used.

Alkylbenzene (A): an alkylbenzene having 1 to 4 alkyl groups having 1 to 19 carbon atoms and a total of 9 to 19 carbon atoms in the alkyl group (preferably 1 to 4 alkyl groups having 1 to 15 carbon atoms, Alkylbenzene having a total of 9 to 15 carbon atoms in the alkyl group)

Alkylbenzene (B): an alkylbenzene having 1 to 4 alkyl groups having 1 to 40 carbon atoms and a total of 20 to 40 carbon atoms in the alkyl group (preferably 1 to 4 alkyl groups having 1 to 30 carbon atoms, An alkylbenzene in which the alkyl group has a total carbon number of 20 to 30)

Specific examples of the alkyl group having 1 to 19 carbon atoms contained in the alkylbenzene (A) include a methyl group, an ethyl group, a propyl group (including all isomers, the same applies hereinafter), a butyl group, a pentyl group, a hexyl group, , Octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group and eicosyl group . These alkyl groups may be linear or branched, and are preferably branched in view of stability and viscosity characteristics. The alkyl group is more preferably a branched alkyl group derived from an oligomer of an olefin such as propylene, butene or isobutylene in view of availability.

The number of alkyl groups in alkylbenzene (A) is 1 to 4, and preferably 1 or 2 (i.e., monoalkylbenzene, dialkylbenzene, or a mixture thereof) in terms of stability and availability.

The alkylbenzene (A) may contain only a single structure alkylbenzene, and may be alkylbenzene having 1 to 4 alkyl groups of 1 to 19 carbon atoms and satisfying the condition that the total number of carbon atoms of the alkyl group is 9 to 19, Structure of alkylbenzene.

Specific examples of the alkyl group having 1 to 40 carbon atoms in the alkylbenzene (B) include a methyl group, an ethyl group, a propyl group (including all isomers, the same applies hereinafter), a butyl group, a pentyl group, a hexyl group, , An octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, , A tetracosyl group, a tetracosyl group, a pentacosyl group, a hexacosyl group, a heptacosyl group, an octacosyl group, a nonacosyl group, a triacontyl group, a hentriacontyl group, a ditriacontyl group, There may be mentioned, for example, a tetraloctanoyl group, a tetrathractoctyl group, a pentatriacontyl group, a hexatriacontyl group, a heptatriacontyl group, an octatriacontyl group, a nonatriacontyl group and a tetracondyl group. These alkyl groups may be linear or branched, and are preferably branched in view of stability and viscosity characteristics. The alkyl group is more preferably a branched alkyl group derived from an oligomer of an olefin such as propylene, butene or isobutylene in view of availability. More preferably, the alkyl group is a linear or branched alkyl group derived from a straight chain alkylating agent such as a straight chain paraffin, a straight chain? -Olefin or a halide thereof, more preferably a branched alkyl group .

The number of alkyl groups in the alkylbenzene (B) is 1 to 4, and preferably 1 or 2 (i.e., monoalkylbenzene, dialkylbenzene, or a mixture thereof) in terms of stability and availability .

The alkylbenzene (B) may contain only a single structure alkylbenzene. If the alkylbenzene has 1 to 4 alkyl groups having 1 to 40 carbon atoms and further satisfies the condition that the total number of carbon atoms of the alkyl group is 20 to 40, Structure of alkylbenzene.

The poly-alpha-olefin (PAO) is, for example, a compound obtained by polymerizing several molecules of a straight chain olefin having 6 to 18 carbon atoms having a double bond at one end only and then hydrogenating. The poly-alpha -olefin may be, for example, isoparaffin having a molecular weight distribution centered on a trimer or tetramer of? -Decene having a carbon number of 10 or? -Dodecene having a carbon number of 12.

Examples of the esters include aromatic esters, dibasic acid esters, polyol esters, complex esters, carbonic esters, and mixtures thereof. The ester is preferably a polyol ester or a complex ester.

Polyol esters are esters of polyhydric alcohols with fatty acids. As the fatty acid, a saturated fatty acid is preferably used. The number of carbon atoms in the fatty acid is preferably 4 to 20, more preferably 4 to 18, still more preferably 4 to 9, and particularly preferably 5 to 9. The polyol ester may be a partial ester in which a part of the hydroxyl groups of the polyhydric alcohol is not esterified but remains a hydroxyl group, may be a complete ester in which all hydroxyl groups are esterified, or may be a mixture of partial esters and complete esters. The hydroxyl value of the polyol ester is preferably 10 mg KOH / g or less, more preferably 5 mg KOH / g or less, and still more preferably 3 mg KOH / g or less.

The proportion of the fatty acid having 4 to 20 carbon atoms in the fatty acid constituting the polyol ester is preferably 20 to 100 mol%, more preferably 50 to 100 mol%, still more preferably 70 to 100 mol% Is 90 to 100 mol%.

Specific examples of the fatty acid having 4 to 20 carbon atoms include butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, , Hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, and icosanoic acid. These fatty acids may be linear or branched. The fatty acid is preferably a fatty acid having a branch at the? -Position and / or a? -Position, more preferably a fatty acid such as 2-methylpropanoic acid, 2-methylbutanoic acid, 2-methylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid and 2-ethylhexadecanoic acid, more preferably 2-ethylhexanoic acid, 3-ethylhexanoic acid, 5,5-trimethylhexanoic acid.

The fatty acid may contain a fatty acid other than the fatty acid having 4 to 20 carbon atoms. The fatty acid other than the fatty acid having 4 to 20 carbon atoms may be, for example, a fatty acid having 21 to 24 carbon atoms. The fatty acids having 21 to 24 carbon atoms may be hexenoic acid, docosanoic acid, tricoloric acid, tetracosanoic acid, and the like, and may be linear or branched.

As the polyhydric alcohol constituting the polyol ester, a polyhydric alcohol having 2 to 6 hydroxyl groups is preferably used. The number of carbon atoms of the polyhydric alcohol is preferably 4 to 12, more preferably 5 to 10. The polyhydric alcohol is preferably a hindered alcohol such as neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), pentaerythritol, dipentaerythritol, More preferably pentaerythritol, dipentaerythritol, or a mixed alcohol of pentaerythritol and dipentaerythritol, because it is an alcohol, and has particularly excellent compatibility with a refrigerant and stable hydrolysis.

The complex ester is, for example, an ester synthesized by the following method (a) or (b).

(a) synthesizing an ester intermediate in which a part of the carboxyl groups of the polybasic acid remains unesterified by adjusting the molar ratio of the polyhydric alcohol to the polybasic acid, and then esterifying the residual carboxyl group with a monohydric alcohol

(b) a method of synthesizing an ester intermediate in which a part of the hydroxyl groups of the polyhydric alcohol remains unesterified by adjusting the molar ratio of the polyhydric alcohol to the polybasic acid, and then esterifying the remaining hydroxyl groups with a monovalent fatty acid

The complex ester obtained by the method (b) tends to have a slightly lower stability than the complex ester obtained by the method of (a), because hydrolysis when used as a refrigerator oil produces relatively strong acid . Therefore, the complex ester is preferably a complex ester obtained by the method of (a) above, which is more stable.

The complex ester is preferably at least one selected from polyhydric alcohols having 2 to 4 hydroxyl groups, at least one selected from polybasic acids having 6 to 12 carbon atoms, monohydric alcohols having 4 to 18 carbon atoms, An ester synthesized with at least one member selected from one kind of acid dissociative group having 2 to 12 carbon atoms.

Examples of the polyhydric alcohol having 2 to 4 hydroxyl groups include neopentyl glycol, trimethylol propane, pentaerythritol and the like. The polyhydric alcohol having 2 to 4 hydroxyl groups is preferably selected from neopentyl glycol and trimethylol propane from the viewpoint of ensuring a suitable viscosity when the complex ester is used as a base oil and obtaining good low- And more preferably neopentyl glycol, from the viewpoint that a wide range of viscosity can be adjusted.

From the viewpoint of excellent lubricity, the polyhydric alcohol constituting the complex ester preferably contains, in addition to the polyhydric alcohol having 2 to 4 hydroxyl groups, a dihydric alcohol having 2 to 10 carbon atoms other than neopentyl glycol do. Examples of the divalent alcohols having 2 to 10 carbon atoms other than neopentyl glycol include ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, 2-methyl-1,3-propanediol, , 2,2-diethyl-1,3-pentanediol, and the like. The dihydric alcohol is preferably butanediol from the viewpoint of excellent characteristics of the lubricant base oil. Examples of butanediol include 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 2,3-butanediol. Butanediol is preferably selected from 1,3-butanediol and 1,4-butanediol from the viewpoint of obtaining good properties. The amount of the divalent alcohol having 2 to 10 carbon atoms other than neopentyl glycol is preferably 1.2 moles or less, more preferably 0.8 moles or less, per 1 mole of the polyhydric alcohol having 2 to 4 hydroxyl groups, Is 0.4 mol or less.

Examples of the polybasic acid having 6 to 12 carbon atoms include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid and trimellitic acid. The polybasic acid is preferably selected from adipic acid and sebacic acid, and more preferably adipic acid, from the viewpoint of excellent balance of characteristics of synthesized esters and easy availability. The amount of the polybasic acid having 6 to 12 carbon atoms is preferably 0.4 to 4 moles, more preferably 0.5 to 3 moles, and still more preferably 0.6 moles per mole of the polyhydric alcohol having 2 to 4 hydroxyl groups To 2.5 moles.

Examples of the monohydric alcohol having 4 to 18 carbon atoms include aliphatic alcohols such as butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, dodecanol and oleyl alcohol. These monohydric alcohols may be linear or branched. The monohydric alcohol having 4 to 18 carbon atoms is preferably a monohydric alcohol having 6 to 10 carbon atoms, more preferably a monohydric alcohol having 8 to 10 carbon atoms, from the viewpoint of balance of characteristics. The above-mentioned monohydric alcohol is more preferably selected from 2-ethylhexanol and 3,5,5-trimethylhexanol from the viewpoint of the low-temperature characteristics of the synthesized complex ester.

Examples of the monovalent fatty acid having 2 to 12 carbon atoms include ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid and dodecanoic acid. These monovalent fatty acids may be linear or branched. The monohydric aliphatic acid having 2 to 12 carbon atoms is preferably a monohydric aliphatic acid having 8 to 10 carbon atoms. Among them, from the viewpoint of low-temperature characteristics, more preferred are monohydric aliphatic acids such as 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid to be.

Examples of the ether include polyvinyl ether, polyalkylene glycol, polyphenyl ether, perfluoroether, and mixtures thereof. The ether is preferably selected from polyvinyl ether and polyalkylene glycol, more preferably polyvinyl ether.

The polyvinyl ether has a structural unit represented by the following general formula (1).

[Chemical Formula 1]

[Wherein R ¹ , R ² and R ³ may be the same or different and each represents a hydrogen atom or a hydrocarbon group, R ⁴ represents a divalent hydrocarbon group or a divalent ether-bonded oxygen-containing hydrocarbon group, R ⁵ Represents a hydrocarbon group, and m represents an integer of 0 or more. When m is 2 or more, a plurality of R ^{4 s} may be the same or different,

The number of carbon atoms of the hydrocarbon group represented by R ¹ , R ² and R ³ is preferably 1 or more, more preferably 2 or more, still more preferably 3 or more, further preferably 8 or less, 7 or less, more preferably 6 or less. At least one of R ¹ , R ² and R ³ is preferably a hydrogen atom, and more preferably all of R ¹ , R ² and R ³ are hydrogen atoms.

The number of carbon atoms of the divalent hydrocarbon group and ether-bonded oxygen-containing hydrocarbon group represented by R ⁴ is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, and preferably 10 or less Preferably 8 or less, more preferably 6 or less. The divalent ether-bonded oxygen-containing hydrocarbon group represented by R ^{4 may} be, for example, a hydrocarbon group having oxygen on the side chain forming an ether bond.

R ⁵ is preferably a hydrocarbon group having 1 to 20 carbon atoms. Examples of such a hydrocarbon group include an alkyl group, a cycloalkyl group, a phenyl group, an aryl group, and an arylalkyl group. The hydrocarbon group is preferably an alkyl group, more preferably an alkyl group having 1 to 5 carbon atoms.

m is preferably at least 0, more preferably at least 1, still more preferably at least 2, and is preferably at most 20, more preferably at most 18, even more preferably at most 16. The average value of m in the total structural units constituting the polyvinyl ether is preferably 0 to 10.

The polyvinyl ether may be a homopolymer composed of one kind selected from the structural units represented by the general formula (1), a copolymer composed of two or more kinds selected from the structural units represented by the general formula (1) Or may be a copolymer composed of structural units and structural units different from each other. By the copolymer of polyvinyl ether, lubricity, insulation, hygroscopicity and the like can be further improved while satisfying the compatibility with refrigerant of refrigerating machine oil. At this time, various characteristics of the refrigerating machine oil can be desired by suitably selecting the kind of the monomer to be the raw material, the kind of the initiator, the ratio of the structural unit in the copolymer, and the like. The copolymer may be either a block copolymer or a random copolymer.

When the polyvinyl ether is a copolymer, the copolymer, the formula is represented by R ⁵ is also one represented by the alkyl group having 1 to the structural unit (1-1) of 3, the general formula (1) also has a carbon number of R ⁵ (1-2) which is an alkyl group having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, and more preferably 3 to 8 carbon atoms. As R ⁵ in the structural unit (1-1), an ethyl group is particularly preferable, and as R ⁵ in the structural unit (1-2), an isobutyl group is particularly preferable. When the polyvinyl ether is a copolymer having the structural units (1-1) and (1-2), the molar ratio of the structural unit (1-1) to the structural unit (1-2) is preferably 5:95 to 95: 5, more preferably from 20:80 to 90:10, and still more preferably from 70:30 to 90:10. When the molar ratio is within the above range, compatibility with the refrigerant can be further improved, and the hygroscopicity can be lowered.

The polyvinyl ether may be composed solely of the structural unit represented by the above formula (1), but may be a copolymer further having a structural unit represented by the following formula (2). In this case, the copolymer may be either a block copolymer or a random copolymer.

(2)

[Wherein R ⁶ to R ⁹ may be the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 20 carbon atoms]

The polyvinyl ether is obtained by polymerizing a vinyl ether monomer corresponding to the structural unit represented by the formula (1) or by copolymerizing a vinyl ether monomer corresponding to the structural unit represented by the formula (1) and an olefinic monomer corresponding to the structural unit represented by the formula Can be produced by copolymerization with a hydrocarbon monomer having a double bond. As the vinyl ether monomer corresponding to the structural unit represented by the formula (1), a monomer represented by the following formula (3) is suitable.

(3)

[In the formula ^{3, R 1, R 2,} R 3, R 4, R 5 and m, R ^1, respectively, in the formula ^{1 R 2, R 3, R} 4, R 5 and shows the same definitions and m ]

The polyvinyl ether preferably has the following terminal structure (A) or (B).

(A) one end is represented by the formula (4) or (5), and the other end is represented by the formula (6) or (7).

[Chemical Formula 4]

[Wherein R ¹¹ , R ²¹ and R ³¹ may be the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 8 carbon atoms, and R ⁴¹ represents a divalent hydrocarbon group of 1 to 10 carbon atoms or a divalent hydrocarbon group of 1 to 10 carbon atoms Ether linkage oxygen-containing hydrocarbon group, R ⁵¹ represents a hydrocarbon group of 1 to 20 carbon atoms, and m represents the same definition as m in formula (1). When m is 2 or more, a plurality of R ^{41 s} may be the same or different,

[Chemical Formula 5]

[Wherein R ⁶¹ , R ⁷¹ , R ⁸¹ and R ⁹¹ may be the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 20 carbon atoms]

[Chemical Formula 6]

[Wherein R ¹² , R ²² and R ³² may be the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 8 carbon atoms, and R ⁴² represents a divalent hydrocarbon group of 1 to 10 carbon atoms or a divalent hydrocarbon group of 1 to 10 carbon atoms Ether bond oxygen-containing hydrocarbon group, R ⁵² represents a hydrocarbon group having 1 to 20 carbon atoms, and m represents the same definition as m in formula (1). When m is 2 or more, a plurality of R ^{42 s} may be the same or different,

(7)

[Wherein R ⁶² , R ⁷² , R ⁸² and R ⁹² may be the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 20 carbon atoms]

(B) one end is represented by the formula (4) or the formula (5), and the other end is represented by the following formula (8).

[Chemical Formula 8]

[Wherein R ¹³ , R ²³ and R ³³ may be the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 8 carbon atoms]

Among these polyvinyl ethers, the polyvinyl ethers of (a), (b), (c), (d) and (e) exemplified below are particularly suitable as base oils.

(a) has one end represented by the formula (4) or the formula (5) and the other end has the structure represented by the formula (6) or (7), and R ¹ , R ² and R ³ in the formula , m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group of 2 to 4 carbon atoms, and R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms.

(b) having only one of the structural units represented by the formula (1), one end of which is represented by the formula (4) and the other end is represented by the formula (6), R ¹ , R ² and R ³ is a hydrogen atom, m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group of 2 to 4 carbon atoms, and R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms.

(c) one end is represented by the formula (4) or (5) and the other end is represented by the formula (8), R ¹ , R ² and R ³ in the formula R ⁴ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms.

(d) a compound having only one structural unit represented by the formula (1) and having a structure represented by the formula (5) at one end and a structure represented by the formula (8) at the other end; R ¹ , R ² and R ³ are all hydrogen atoms, m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group of 2 to 4 carbon atoms, and R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms.

(e) of the above (a), (b), (c) and (d) is of a one, R ⁵ is wherein R ⁵ and a hydrocarbon group structure unit of 1 to 3 carbon atoms in the formula (I) having 3 to 20 carbon atoms Polyvinyl ether having a structural unit which is a hydrocarbon group.

The weight average molecular weight of the polyvinyl ether is preferably 500 or more, more preferably 600 or more, further preferably 3000 or less, more preferably 2000 or less, still more preferably 1500 or less. When the weight average molecular weight of the polyvinyl ether is 500 or more, the lubricity under the coexistence of the refrigerant is excellent. If the weight average molecular weight is 3000 or less, the composition range exhibiting compatibility with the refrigerant under a low temperature condition is widened, and it is possible to suppress the defective lubrication of the refrigerant compressor and the inhibition of heat exchange in the evaporator.

The number average molecular weight of the polyvinyl ether is preferably 500 or more, more preferably 600 or more, further preferably 3000 or less, more preferably 2000 or less, still more preferably 1500 or less. When the number average molecular weight of the polyvinyl ether is 500 or more, the lubricity under the coexistence of the refrigerant is excellent. When the number average molecular weight is 3000 or less, the composition range showing compatibility with the refrigerant under a low temperature condition is widened, and it is possible to suppress the defective lubrication of the refrigerant compressor and the inhibition of heat exchange in the evaporator.

The weight average molecular weight and the number average molecular weight of the polyvinyl ether mean weight average molecular weight and number average molecular weight (polystyrene (standard sample) conversion value) obtained by GPC analysis, respectively. The weight average molecular weight and the number average molecular weight can be measured, for example, as follows.

Chloroform is used as a solvent and diluted to prepare a solution having a polyvinyl ether concentration of 1% by mass. This solution is analyzed using a GPC apparatus (Waters Alliance 2695). The flow rate of the solvent is 1 ml / min, the analytical molecular weight is 100 to 10000, and the analysis is carried out using a refractive index detector. Further, the relationship between the column retention time and the molecular weight is determined using a polystyrene standard having a definite molecular weight, a calibration curve is prepared separately, and the molecular weight of the sample is determined from the obtained retention time.

The degree of unsaturation of the polyvinyl ether is preferably 0.04 meq / g or less, more preferably 0.03 meq / g or less, and still more preferably 0.02 meq / g or less. The peroxide value of the polyvinyl ether is preferably 10.0 meq / kg or less, more preferably 5.0 meq / kg or less, and still more preferably 1.0 meq / kg or less. The carbonyl content of the polyvinyl ether is preferably 100 ppm by weight or less, more preferably 50 ppm by weight or less, further preferably 20 ppm by weight or less. The hydroxyl value of the polyvinyl ether is preferably not more than 10 mg KOH / g, more preferably not more than 5 mg KOH / g, still more preferably not more than 3 mg KOH / g.

The unsaturation degree, peroxide value and carbonyl value in the present invention refer to the values measured by the standard maintenance analysis test method established by the Japanese Society for the Study of Emulsification, respectively. That is, the degree of unsaturation in the present invention is obtained by reacting a sample with a solution of Wijs (ICl-acetic acid solution) and leaving the solution in a dark place. Thereafter, the excess ICl is reduced with iodine and the iodine is titrated with sodium thiosulfate And the iodine value is converted into the vinyl equivalent (meq / g). The peroxide value in the present invention refers to a value (meq / kg) obtained by adding potassium iodide to a sample, titrating the generated free iodine with sodium thiosulfate, and converting the free iodine to the milliequivalent number per 1 kg of the sample. The carbonyl number in the present invention is obtained by reacting 2,4-dinitrophenylhydrazine with a sample to generate color-forming quinide ions, measuring the absorbance of the sample at 480 nm, and using Shin Nam aldehyde as a standard (Ppm by weight) in terms of the amount of carbonyl based on the obtained calibration curve. The hydroxyl value in the present invention means the hydroxyl value measured in accordance with JIS K0070: 1992.

Examples of the polyalkylene glycols include polyethylene glycol, polypropylene glycol, and polybutylene glycol. The polyalkylene glycol has oxyethylene, oxypropylene, oxybutylene, and the like as a structural unit. Polyalkylene glycols having these structural units can be obtained by ring-opening polymerization using ethylene oxide, propylene oxide, and butylene oxide, which are monomers, as raw materials.

Examples of the polyalkylene glycol include compounds represented by the following formula (9).

[Chemical Formula 9]

R ^? - [(OR ^? ) _F- OR ^? ] _G

Wherein R ^{? Represents} a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or a residue of a compound having 2 to 8 hydroxyl groups, and R ^? Is an alkylene group having 2 to 4 carbon atoms represents a group, R ^γ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or acyl of 2 to 10 carbon atoms, f represents an integer of 1 to 80, and g represents an integer of 1 to 8;

Alkyl group represented by R ^α, R ^γ is, or may be any of straight chain, branched, cyclic would. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6. When the number of carbon atoms in the alkyl group exceeds 10, the compatibility with the refrigerant tends to be lowered.

Alkyl portion of acyl groups represented by R ^α, R ^γ is, or may be any of straight chain, branched, cyclic would. The carbon number of the acyl group is preferably 2 to 10, more preferably 2 to 6. When the number of carbon atoms of the acyl group exceeds 10, compatibility with the refrigerant is lowered and phase separation may occur.

If the group, all groups represented by R ^α, R ^γ, or if both the acyl group, may be the same or different groups represented by R ^α, R ^γ. When g is 2 or more, a plurality of groups represented by R ^? and R ^? in the same molecule may be the same or different.

When the group represented by R &^lt; ^alpha > is a residue of a compound having 2 to 8 hydroxyl groups, the compound may be in a chain form or in a cyclic form.

At least one of R ^{? And} R ^{? Is} preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group, from the viewpoint of excellent compatibility. From the viewpoint of excellent thermal and chemical stability, both of R ^? And R ^{? Are} preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group. From the viewpoints of ease of manufacture and cost, either one of R ^? And R ^? Is an alkyl group (more preferably an alkyl group having 1 to 4 carbon atoms) and the other is a hydrogen atom, one is a methyl group, More preferably a hydrogen atom. From the viewpoint of excellent lubricity and sludge solubility, it is preferable that both of R ^? And R ^? Are hydrogen atoms.

R ^{? Represents} an alkylene group having 2 to 4 carbon atoms, and specific examples of the alkylene group include an ethylene group, a propylene group and a butylene group. The oxyalkylene group which is a repeating unit represented by OR &^lt; ^beta > includes an oxyethylene group, an oxypropylene group and an oxybutylene group. The oxyalkylene group represented by the formula (OR &^lt; ^beta ) &^gt; _f may be composed of one oxyalkylene group or may be composed of two or more oxyalkylene groups.

The polyalkylene glycol represented by the general formula (9) is preferably a copolymer comprising an oxyethylene group (EO) and an oxypropylene group (PO) from the viewpoint of excellent compatibility with a refrigerant and excellent viscosity-temperature characteristics. In this case, the ratio of the oxyethylene group (EO / (PO + EO)) in the total sum of the oxyethylene group and the oxypropylene group is preferably 0.1 to 0.8, more preferably Is 0.3 to 0.6. EO / (PO + EO) is preferably 0 to 0.5, more preferably 0 to 0.2, still more preferably 0 (i.e., propylene oxide homopolymer) in view of excellent hygroscopicity and heat and oxidation stability.

f represents the number of repeating units (degree of polymerization) of the oxyalkylene group OR &^lt; ^beta > and is an integer of 1 to 80; g is an integer of 1 to 8; For example, when R ^{< alpha} > is an alkyl group or an acyl group, g is 1. When R ^? Is a residue of a compound having 2 to 8 hydroxyl groups, g is the number of hydroxyl groups contained in the compound.

In the polyalkylene glycol represented by the general formula (9), the average value of the product of f and g (f x g) is preferably 6 to 80 from the viewpoint of satisfactorily satisfying the required performance as the refrigeration oil.

The weight average molecular weight of the polyalkylene glycol is preferably 500 or more, more preferably 600 or more, further preferably 3000 or less, more preferably 2000 or less, still more preferably 1500 or less. If the weight average molecular weight of the polyalkylene glycol is 500 or more, the lubricity under the coexistence of the refrigerant is excellent. If the weight average molecular weight is 3000 or less, the composition range exhibiting compatibility with the refrigerant under a low temperature condition is widened, and it is possible to suppress the defective lubrication of the refrigerant compressor and the inhibition of heat exchange in the evaporator.

The number average molecular weight of the polyalkylene glycol is preferably 500 or more, more preferably 600 or more, further preferably 3000 or less, more preferably 2000 or less, still more preferably 1500 or less. When the number average molecular weight of the polyalkylene glycol is 500 or more, the lubricity under the coexistence of the refrigerant is excellent. When the number average molecular weight is 3000 or less, the composition range showing compatibility with the refrigerant under a low temperature condition is widened, and it is possible to suppress the defective lubrication of the refrigerant compressor and the inhibition of heat exchange in the evaporator.

The weight average molecular weight and the number average molecular weight of the polyalkylene glycol mean the weight average molecular weight and the number average molecular weight (in terms of polypropylene glycol (standard sample)) obtained by GPC analysis, respectively. The weight average molecular weight and the number average molecular weight can be measured, for example, as follows.

Chloroform is used as a solvent, and the solution is diluted to prepare a solution having a polyalkylene glycol concentration of 1% by mass. This solution is analyzed using a GPC apparatus (Waters Alliance 2695). The flow rate of the solvent is 1 ml / min, the analytical molecular weight is 100 to 10000, and the analysis is carried out using a refractive index detector. Further, the relationship between the column retention time and the molecular weight is determined by using a polyalkylene glycol standard having a definite molecular weight, and a calibration curve is prepared separately, and then the molecular weight of the sample is determined at the obtained retention time.

The hydroxyl value of the polyalkylene glycol is preferably not more than 100 mg KOH / g, more preferably not more than 50 mg KOH / g, still more preferably not more than 30 mg KOH / g, most preferably not more than 10 mg KOH / g.

Polyalkylene glycols can be synthesized using a known method (" alkylene oxide polymer ", Shibata Mitsuta et al., Kaibando, published on November 20, 1990). For example, alcohol (R ^α OH; R ^α has the formula 9 represent the same definitions as in the R ^α) to addition polymerization and, more etherified or esters of the terminal hydroxyl group to the screen at least one kind of predetermined alkylene oxide , Whereby the polyalkylene glycol represented by the general formula (9) can be obtained. When two or more alkylene oxides are used in the above production process, the obtained polyalkylene glycol may be any of a random copolymer and a block copolymer. However, from the viewpoint that oxidation stability and lubricity tend to be more excellent, Is preferably a random copolymer in that it is a block copolymer and tends to have a better low-temperature fluidity.

The degree of unsaturation of the polyalkylene glycol is preferably 0.04 meq / g or less, more preferably 0.03 meq / g or less, and still more preferably 0.02 meq / g or less. The peroxide value is preferably 10.0 meq / kg or less, more preferably 5.0 meq / kg or less, and still more preferably 1.0 meq / kg or less. The carbonyl content is preferably not more than 100 ppm by weight, more preferably not more than 50 ppm by weight, further preferably not more than 20 ppm by weight.

The lubricant base oil is preferably at least one selected from oxygen-containing channels, and more preferably at least one selected from esters and ethers.

The kinematic viscosity of the lubricating base oil at 40 캜 may preferably be 3 mm 2 / s or higher, more preferably 4 mm 2 / s or higher, and still more preferably 5 mm 2 / s or higher. The kinematic viscosity at 40 캜 of the lubricating base oil may be preferably 1000 mm 2 / s or less, more preferably 500 mm 2 / s or less, and further preferably 400 mm 2 / s or less. The kinematic viscosity at 100 캜 of the lubricating oil base oil may be preferably 1 mm 2 / s or more, and more preferably 2 mm 2 / s or more. The kinematic viscosity at 100 占 폚 of the lubricating base oil may be preferably 100 mm2 / s or less, more preferably 50 mm2 / s or less. The kinematic viscosity in the present invention means the kinematic viscosity measured in accordance with JIS K2283: 2000.

The content of the lubricating base oil may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the refrigerating machine flow rate.

The compound represented by the formula (A) is preferably a compound represented by any one of the following formulas (A-1) to (A-3).

[A-1]

[A-2]

[A-3]

In the formula A-1) to ^{(A-3, R a, R} b, R c and X are, respectively, have the same meaning as in formula A R ^a, R ^b, R ^c and X.

The carbon number of the monovalent hydrocarbon group represented by R ^a and R ^b may be from 2 to 18, from 2 to 16, from 2 to 14, from 2 to 12, from 2 to 10, or from 2 to 8. The monovalent hydrocarbon group may be a straight chain or branched alkyl group. The carbon number of the divalent hydrocarbon group represented by R ^{c may} be 1 to 4, 1 to 3, 1 to 2 or 1. The bivalent hydrocarbon group may be a linear or branched alkylene group.

The polar group represented by X may have an oxygen atom. The polar group may be, for example, a -OH group, -COOH group, -COOR group, -CONHNH ₂ group, -CONH ₂ group, -NR ₂ group, -CN group, -CH (COOH) CH ₂ COOH group, CH (COOR) CH ₂ COOH group, or a group represented by any of the following formulas (x-1) to (x-4)

[Formula x-1]

[Formula (X-2)

[Formula X-3]

[Formula X-4]

The polar group represented by X is preferably -OH group, -COOH group, -COOR group, -CH (COOH) CH ₂ COOH group, or -CH (COOR) CH ₂ COOH group. R in the -COOR group, -NR ₂ group and -CH (COOR) CH ₂ COOH group may be a monovalent hydrocarbon group, or may be a linear or branched alkyl group. The number of carbon atoms of the monovalent hydrocarbon group and the alkyl group may be 1 to 12, 1 to 8, or 1 to 2.

The compound represented by the formula (A) may be a compound represented by the following formula (A-4) as a preferred embodiment.

[A-4]

In formula (A-4), R ^d and R ^e each independently represent a straight-chain or branched alkyl group having 2 to 8 carbon atoms, X ^a represents -OH group, -COOH group or -COOR 'group (R' To 8 < RTI ID = 0.0 > linear < / RTI >

The content of the compound represented by the formula (A) may be 0.005 mass% or more, 0.01 mass% or more, or 0.02 mass% or more, and 0.1 mass% or less, 0.2 mass% or less or 1 mass% or less, based on the refrigerating machine flow rate. The content of the compound represented by the formula (A) is in the range of 0.005 to 0.1 mass%, 0.005 to 0.2 mass%, 0.005 to 1 mass%, 0.01 to 0.1 mass%, 0.01 to 0.2 mass%, 0.01 to 1 mass% %, 0.02 to 0.1 mass%, 0.02 to 0.2 mass%, or 0.02 to 1 mass%.

The refrigerator oil may further contain an epoxy compound. Examples of the epoxy compounds include glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, oxirane compounds, alkyloxirane compounds, alicyclic epoxy compounds, epoxidized fatty acid monoesters, and epoxidized vegetable oils. These epoxy compounds may be used singly or in combination of two or more.

The glycidyl ether type epoxy compound may be, for example, an aryl glycidyl ether type epoxy compound or an alkyl glycidyl ether type epoxy compound represented by the following formula (B-1).

[Formula B-1]

In the above formula (B-1), R ^f represents an aryl group having 6 to 18 carbon atoms or an alkyl group having 5 to 18 carbon atoms.

The glycidyl ether type epoxy compound represented by the formula (B-1) is preferably selected from the group consisting of n-butylphenylglycidyl ether, i-butylphenylglycidylether, sec-butylphenylglycidylether, Hexyl phenyl glycidyl ether, heptyl phenyl glycidyl ether, octyl phenyl glycidyl ether, nonyl phenyl glycidyl ether, decyl phenyl glycidyl ether, decyl glycidyl ether, Cidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, or 2-ethylhexyl glycidyl ether.

The glycidyl ether type epoxy compound may be a compound other than the epoxy compound represented by the formula (B-1), specifically, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl Diallyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ether, polyalkylene glycol diglycidyl ether, and the like.

The glycidyl ester type epoxy compound may be, for example, a compound represented by the following formula (B-2).

[Formula B-2]

In the above formula (B-2), R ^g represents an aryl group having 6 to 18 carbon atoms, an alkyl group having 5 to 18 carbon atoms, or an alkenyl group having 5 to 18 carbon atoms.

The glycidyl ester type epoxy compound represented by the formula (B-2) is preferably selected from glycidyl benzoate, glycidyl neodecanoate, glycidyl-2,2-dimethyl octanoate, glycidyl Acrylate, or glycidyl methacrylate.

The alicyclic epoxy compound is a compound represented by the following formula (B-3) and having a partial structure in which the carbon atom constituting the epoxy group directly constitutes an alicyclic ring.

[Formula B-3]

The alicyclic epoxy compound is, for example, 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3 ', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis Epoxy cyclohexylmethyl) adipate, exo-2,3-epoxy norbornane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 2- (7-oxabicyclo [4.1 -0] hept-3-yl) -spiro (1, 3-dioxane-5,3'- [7] oxabicyclo [4.1.0] heptane, 4- 2-epoxy-2-methylcyclohexane, 2-epoxy-2-methylcyclohexane and 4-epoxyethyl-1,2-epoxycyclohexane.

Examples of the allyloxirane compound include 1,2-epoxystyrene, alkyl-1,2-epoxystyrene, and the like.

Examples of the alkyloxylan compound include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1,2- 1,2-epoxy dodecane, 1,2-epoxydecane, 1,2-epoxy dodecane, 1,2-epoxy dodecane, Hexadecane, 1,2-epoxyheptadecane, 1,2-epoxyoctadecane, 1,2-epoxynonadecane, 1,2-epoxycyclohexane, and the like.

Examples of the epoxidized fatty acid monoesters include esters of an epoxidized fatty acid having 12 to 20 carbon atoms with an alcohol having 1 to 8 carbon atoms or a phenol or an alkylphenol. The epoxidized fatty acid monoesters are preferably butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl or butylphenyl esters of epoxystearic acid.

Examples of the epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil and cottonseed oil.

When the refrigerating machine oil contains both the compound represented by the chemical formula A and the epoxy compound, the refrigerating machine oil is excellent in not only abrasion resistance but also stability, as compared with the conventional refrigerator machine oil containing, for example, an acidic phosphate ester and an epoxy compound. The epoxy compound is preferably at least one member selected from a glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound and an alicyclic epoxy compound from the viewpoint of compatibility between abrasion resistance and stability, , A glycidyl ether type epoxy compound, and a glycidyl ester type epoxy compound.

The content of the epoxy compound is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more, based on the flow rate of the refrigerating machine from the viewpoint of improvement of stability. The content of the epoxy compound is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and still more preferably 2.0% by mass or less, based on the refrigerating machine flow rate, from the viewpoint of improvement of lubricity.

The refrigerator oil may further contain other additives. Examples of other additives include, but are not limited to, acid scavengers other than epoxy compounds, antioxidants, extreme pressure agents, oil agents, defoaming agents, metal deactivators, wear resistance agents other than the compound represented by the formula A, viscosity index improvers, Dispersants and the like. The content of these additives may be 10% by mass or less or 5% by mass or less based on the flow rate of the refrigerator.

Among the other additives, the refrigerator oil preferably further contains at least one of an antioxidant and an abrasion preventing agent other than the compound represented by the general formula (A). The antioxidant may be a phenol-based antioxidant such as 2,6-di-tert.-butyl-p-cresol or bisphenol A, or an amine-based antioxidant such as alkylphenyl naphthylamine or dialkyldiphenylamine. The abrasion preventing agent other than the compound represented by the formula (A) may be a phosphorus-based abrasion preventing agent such as a phosphoric acid ester, an acidic phosphate ester, a thiophosphoric ester, an amine salt of an acidic phosphate ester, a chlorinated phosphate ester or a phosphorous ester.

The kinematic viscosity of the refrigerator oil at 40 캜 may preferably be 3 mm 2 / s or higher, more preferably 4 mm 2 / s or higher, and still more preferably 5 mm 2 / s or higher. The kinematic viscosity at 40 캜 of the refrigerator oil may be preferably 500 mm 2 / s or less, more preferably 400 mm 2 / s or less, and still more preferably 300 mm 2 / s or less.

The kinematic viscosity at 100 캜 of the refrigerator oil may preferably be 1 mm 2 / s or more, and more preferably 2 mm 2 / s or more. The kinematic viscosity at 100 캜 of the refrigerator oil may be preferably 100 mm 2 / s or less, more preferably 50 mm 2 / s or less.

The pour point of the refrigerator oil is preferably -10 ° C or lower, more preferably -20 ° C or lower. The pour point in the present invention means a pour point measured in accordance with JIS K2269-1987.

The volume resistivity of the refrigerator oil may preferably be 1.0 x 10 ⁹ Ω · m or more, more preferably 1.0 × 10 ¹⁰ Ω · m or more, and still more preferably 1.0 × 10 ¹¹ Ω · m or more. The volume resistivity in the present invention means the volume resistivity at 25 占 폚 measured in accordance with JIS C2101: 1999.

The moisture content of the refrigerator oil may be preferably 200 ppm or less, more preferably 100 ppm or less, and even more preferably 50 ppm or less, based on the freezer flow rate.

The acid value of the refrigerator oil may be preferably 1.0 mg KOH / g or less, more preferably 0.1 mg KOH / g or less. The acid value in the present invention means an acid value measured in accordance with JIS K2501: 2003.

The content of the refrigerator oil may preferably be 100 ppm or less, more preferably 50 ppm or less. The ash in the present invention means the ash measured in accordance with JIS K2272: 1998.

The refrigerator oil according to the present embodiment is used together with the refrigerant. Examples of the refrigerant include a saturated fluorinated hydrocarbon refrigerant, an unsaturated fluorinated hydrocarbon refrigerant, a hydrocarbon refrigerant, a fluorinated ether refrigerant such as a perfluoroether, a bis (trifluoromethyl) sulfide refrigerant, a trifluoromethyl iodide methane refrigerant, and ammonia, Natural refrigerants, and mixed refrigerants containing one or more of these refrigerants.

The saturated fluorohydrocarbon refrigerant is preferably a saturated fluorinated hydrocarbon having 1 to 3 carbon atoms, more preferably 1 to 2 carbon atoms. Specifically, it is preferable to use at least one of difluoromethane (R32), trifluoromethane (R23), pentafluoroethane (R125), 1,1,2,2-tetrafluoroethane (R134) 2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a), 1,1-difluoroethane (R152a), fluoroethane (R161), 1,1,1,2 , 3,3,3-heptafluoropropane (R227ea), 1,1,1,2,3,3-hexafluoropropane (R236ea), 1,1,1,3,3,3-hexafluoro Propane (R236fa), 1,1,1,3,3-pentafluoropropane (R245fa), and 1,1,1,3,3-pentafluorobutane (R365mfc), or a mixture of two or more thereof .

The saturated hydrofluorocarbon refrigerant is appropriately selected from among the above in accordance with the use and the required performance, for example, R32 alone; R23 alone; R134a alone; R125 alone; A mixture of R134a / R32 = 60 to 80 mass% / 40 to 20 mass%; A mixture of R32 / R125 = 40 to 70 mass% / 60 to 30 mass%; A mixture of R125 / R143a = 40 to 60 mass% / 60 to 40 mass%; A mixture of R134a / R32 / R125 = 60 mass% / 30 mass% / 10 mass%; A mixture of R134a / R32 / R125 = 40 to 70 mass% / 15 to 35 mass% / 5 to 40 mass%; A mixture of R125 / R134a / R143a = 35 to 55 mass% / 1 to 15 mass% / 40 to 60 mass% may, for example, be mentioned as preferred examples. More specifically, a mixture of R134a / R32 = 70/30 mass%; A mixture of R32 / R125 = 60/40 mass%; A mixture of R32 / R125 = 50/50 mass% (R410A); A mixture of R32 / R125 = 45/55 mass% (R410B); A mixture of R125 / R143a = 50/50% by mass (R507C); A mixture of R32 / R125 / R134a = 30/10/60 mass%; A mixture of R32 / R125 / R134a = 23/25/52 mass% (R407C); A mixture (R407E) of R32 / R125 / R134a = 25/15/60 mass%; A mixture (R404A) of R125 / R134a / R143a = 44/4/52 mass% may be used.

The unsaturated fluorohydrocarbon (HFO) refrigerant is preferably an unsaturated fluorinated hydrocarbon having 2 to 3 carbon atoms, more preferably fluoropropene, and still more preferably fluoropropene having 3 to 5 fluorine atoms. The unsaturated hydrofluorocarbon refrigerant is preferably selected from the group consisting of 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3,3-tetrafluoropropene (HFO-1234ze) 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,2,3,3-tetrafluoropropene (HFO-1234ye), and 3,3,3-trifluoropropene (HFO-1243zf), or a mixture of two or more thereof. The unsaturated hydrofluorocarbon refrigerant is preferably one or more selected from HFO-1225ye, HFO-1234ze and HFO-1234yf in view of the refrigerant properties. The unsaturated hydrofluorocarbon refrigerant may be fluoroethylene, and preferably 1,1,2,3-trifluoroethylene (HFO-1123). The unsaturated hydrofluorocarbon refrigerant may be 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd), and may be cis-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (Z)), trans-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (E)) and mixtures thereof.

The hydrocarbon refrigerant is preferably a hydrocarbon having 1 to 5 carbon atoms, more preferably a hydrocarbon having 2 to 4 carbon atoms. Specific examples of the hydrocarbon include hydrocarbons such as methane, ethylene, ethane, propylene, propane (R290), cyclopropane, n-butane, isobutane, cyclobutane, methylcyclopropane, And mixtures of two or more species. Of these, hydrocarbon refrigerants which are gaseous at 25 ° C and 1 atmospheric pressure are preferably used, and propane, normal butane, isobutane, 2-methylbutane or a mixture thereof is more preferably used.

The refrigerant to be used together with the refrigerating machine oil according to the present embodiment may be a mixed refrigerant containing one or more kinds selected from the refrigerants. For example, the refrigerant may be one or two selected from an unsaturated hydrocarbon (HFO) One or more refrigerants selected from a hydrocarbon refrigerant and a natural refrigerant are added to the mixed refrigerant mixture of one or more kinds of refrigerants selected from the group consisting of saturated or unsaturated hydrocarbons (HFC) refrigerants, May be mixed refrigerant. More specifically, the refrigerant may be one or more HFO refrigerants selected from HFO-1225ye, HFO-1234ze, HFO-1234yf, HFO-1123 and HCFO-1224yd, and R32, R134a, R125 , R152a, R227ea, R236fa and the like, or a mixed refrigerant obtained by additionally mixing a hydrocarbon refrigerant such as R290, R600a or a natural refrigerant such as R744 to the mixed refrigerant, good.

The mixing ratio (mass ratio) of the respective refrigerants in these mixed refrigerants is preferably in the range of 5 to 95/95 to 5/0 to 20, preferably 15 to 85/85 to 15/15, in the range of HFO refrigerant / HFC refrigerant / 0 to 10 may be used. These mixed refrigerants are more specifically refrigerants such as R444A, R445A, R446A, R447A, R447B, R448A, R449A, R449C, R452B, R454B, R454C, R455A, R456A, R457A, R458A, R459A, R459B, R460B, R461A, But the present invention is not limited thereto.

The refrigerator oil according to the present embodiment is usually present in the refrigerator in the state of the refrigerant composition for refrigerators mixed with the refrigerant. That is, the working fluid composition for a refrigerator according to the present embodiment contains the refrigerator oil and the refrigerant. The content of refrigerating machine oil in the refrigerating machine working fluid composition may be preferably 1 to 500 parts by mass, more preferably 2 to 400 parts by mass based on 100 parts by mass of the refrigerant.

The working fluid composition for a refrigerator oil and a refrigerator according to the present embodiment may be applied to an air conditioner, a refrigerator, an open or closed type car air conditioner, a dehumidifier, a water heater, a freezer, a refrigerator, a vending machine, , A refrigerator such as a chemical plant, a refrigerator having a centrifugal compressor, and the like.

[Example]

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the examples.

In the examples and comparative examples, refrigerator oil having the composition (% by mass based on the refrigerating machine flow rate) shown in Tables 1 to 3 was prepared using the following base oils and additives.

(Base oil)

Base oil 1: A polyol ester (having a kinetic viscosity at 40 ° C: 67.2 mm 2 / s, viscosity index: 35/65) and a mixed fatty acid of pentaerythritol and 2-methylpropanoic acid / 3,5,5-trimethylhexanoic acid : 84)

Base oil 2: 2-ethylhexanol (2.4 moles) was further reacted with the ester intermediate obtained by reacting adipic acid (2.4 moles) with neopentyl glycol (1 mole) and 1,4-butanediol (0.3 mole) The complex ester (kinematic viscosity at 40 캜: 68.2 mm 2 / s, viscosity index: 144) obtained by removing one unreacted material by distillation,

Base oil 3: polyethyl vinyl ether (number average molecular weight: 1900, kinematic viscosity at 40 占 폚: 71.0 mm2 / s, kinematic viscosity at 100 占 폚: 8.6 mm2 / s, viscosity index: 89)

Base oil 4: A polyol ester (kinematic viscosity at 40 캜: 68 mm 2 / s) of pentaerythritol and a mixed fatty acid of 2-ethylhexanoic acid / 3,5,5-trimethylhexanoic acid (mass ratio: 50/50)

Base oil 5 3,5,5-trimethylhexanol (2.4 moles) was added to the ester intermediate obtained by reacting adipic acid (2.4 moles) with neopentyl glycol (1 mole) and 1,4-butanediol (0.3 mole) (Kinematic viscosity at 40 DEG C: 150 mm < 2 > / s) obtained by removing the remaining unreacted material by distillation,

Base oil 6: A polyol ester (kinematic viscosity at 40 캜: 220 mm 2 / s) of dipentaerythritol and a mixed fatty acid of 2-ethylhexanoic acid / 3,5,5-trimethylhexanoic acid (mass ratio: 50/50)

Base oil 7: polyol ester (kinematic viscosity at 40 캜: 68 mm 2 / s) of pentaerythritol and pentanoic acid / 3,5,5-trimethylhexanoic acid mixed fatty acid (mass ratio: 25/75)

Base oil 8: polypropylene glycol dimethyl ether (number average molecular weight (Mn): 1000, kinematic viscosity at 40 占 폚: 46.0 mm2 / s, viscosity index: 190)

(additive)

A1: A compound represented by the following formula (A-1-1)

[A-1-1]

A2: A compound represented by the following formula (A-1-2)

[A-1-2]

A3: A compound represented by the following formula (A-1-3)

[Formula A-1-3]

a1: Tricresyl phosphate

a2: Di (n-octyl) acid phosphate

B1: glycidyl neodecanoate

B2: 2-ethylhexyl glycidyl ether

Each refrigerator oil of the examples and comparative examples was subjected to the following abrasion resistance test. The results are shown in Tables 1 to 3.

(Abrasion resistance test)

The abrasion resistance test was performed by a high-speed four-ball test. SUJ-2 was used as a ball, and the test was conducted under the conditions of a test flow rate of 20 mL, a test temperature of 80 캜, a number of revolutions of 1200 rpm, a load load of 294 N, and a test time of 30 minutes. The abrasion resistance was evaluated by using an average value of the abrasion loss diameter (mm) of the fixing ball (fixing ball).

[Table 1]

[Table 2]

[Table 3]

Further, in Example 8, refrigerator oils of Examples 10 to 16 were prepared using each of the following base oils in place of base oil 1: These refrigerator oils were evaluated for wear resistance in the same manner as described above, and the same effects as those of Examples 1 to 9 were obtained.

(Example 10) Base oil 4

(Example 11) Mixing base oil 1: base oil 4 = 60: 40 (mass ratio)

(Example 12) Mixing base oil 1: base oil 5 = 80: 20 (mass ratio)

(Example 13) Base oil 4: base oil 5 = 80: 20 (mass ratio)

(Example 14) Base oil 4: base oil 6 = 80:20 (mass ratio)

(Example 15) Base oil 7

(Example 16) Base oil 8

In addition, to each refrigerator oil of Example 8 and Examples 10 to 16, 1 mass% of tricresyl phosphate, which is an orthophosphoric ester, and 2,6-di-tert-butyl-p-cresol (DBPC) 0.5% by mass were further contained to prepare refrigerator oils of Examples 17 to 24, respectively. These refrigerating machine oils were evaluated for abrasion resistance as described above, and the same effects as in Examples 1 to 9 were obtained.

Examples 7 to 9 and Comparative Example 5 and Comparative Example 6 were subjected to the following stability test. The results are shown in Table 4.

(Stability test)

In accordance with JIS K2211: 2009 (autoclave test), stability at the time of refrigerant mixing was evaluated. 30 g of a refrigerator oil whose moisture content was adjusted to 1000 ppm was weighed into an autoclave and 30 g of a catalyst (iron, copper and aluminum wires, both outer diameter 1.6 mm and length 50 mm) and R32 were sealed, And heated for 168 hours. The acid value (acid value after the test) was measured for each freezer oil after the test in accordance with JIS K2501: 2003.

[Table 4]

The refrigerator oils of Examples 10 to 24 were evaluated for stability in the same manner as described above, and the same effects as those of Examples 7 to 9 were obtained. In addition, with respect to Examples 17 to 24, stability in the case where the refrigerant was changed from R32 to HFO-1234yf in the above stability test was also evaluated. As a result, good stability was shown.

As described above, the present invention is not limited to the embodiments and examples disclosed in the specification, and can be appropriately changed without departing from the gist or spirit of the invention which can be grasped from the claims and the entire specification, Refrigerator oil and the like are also to be understood as being included in the technical scope of the present invention.

Claims (6)

A refrigerator oil (refrigerator oil) containing a lubricating base oil and a compound represented by the following formula (A).
(A)

[Wherein R ^a and R ^b each independently represent a monovalent hydrocarbon group, R ^c represents a divalent hydrocarbon group, X represents a polar group, Z ^a and Z ^b each independently represents an oxygen atom or a sulfur atom Lt; / RTI & The refrigerator oil according to claim 1, wherein the lubricating base oil contains at least one kind of acidic phosphorus (oxygenated oil) selected from the group consisting of esters and ethers. The refrigerator oil according to claim 1 or 2, further comprising an epoxy compound. The epoxy resin composition according to claim 3, wherein the epoxy compound is at least one selected from the group consisting of a glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an oxirane compound, an alkyloxirane compound, an alicyclic epoxy compound, an epoxidized fatty acid monoester, A vegetable oil, and a vegetable oil. The refrigerator oil according to claim 3, wherein as the epoxy compound, at least one selected from the group consisting of a glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, and an alicyclic epoxy compound is contained. 6. The refrigerator oil according to any one of claims 1 to 5, wherein the polar group has an oxygen atom.